An Algorithmic Procedure for Designing Hybrid FIR/IIR Digital Filters
M. R. Campbell, Ronald E. Crochiere, L. R. Rabiner · Bell System Technical Journal · 1976
An algorithmic procedure for designing hybrid FIR/IIR digital filters is proposed and evaluated in this paper. The design is implemented as a two-stage optimization in which a Hooke and Jeeves optimization procedure is used to optimize the IIR component of the filter and the McClellan et al. optimization procedure is used to optimize the FIR component of the filter. To evaluate this method, a set of eight low-pass filters were designed in which a single complex conjugate pole pair was used as the IIR component. The resulting designs were compared and contrasted with standard IIR low-pass filters and the optimal FIR, linear-phase, low-pass filter in terms of multiplications, storage, and group delay properties.